Figure 3

Tlr1/2 and Cxcr3 pathways redundantly control the accumulation of Olig2:GFP⁺ cells but not their maintenance at the injury site in the zebrafish telencephalon. (A) Scheme of the experimental setup to address the role of Cxcr3 and Tlr1/2 in the reactive gliosis 4 days after injury. (B–E) Micrographs of telencephalic sections obtained after 4 dpi depicting Olig2:GFP⁺ and Sox10⁺ oligodendroglia reactivity with vehicle (B), Tlr1/2 inhibitor (C), Cxcr3 inhibitor (D), and double-inhibitor (E) treatments. (F) Graph showing the density of Olig2:GFP⁺ cells located at the injury site after vehicle, Tlr1/2 inhibitor (CU CPT22), Cxcr3 inhibitor (NBI 74330) and double-inhibitor combination (NBI 74330 + CU CPT22) treatment. Note that only the double-inhibitor cocktail reduces the number of Olig2:GFP⁺ cells accumulating at the injury site. Data shown as mean ± SEM; each data point represents one animal. p-values are based on a one-way ANOVA (p-value = 4.074 × 10⁻³) with a post-hoc Dunnett test (Many-to-One). (G) Experimental outline to assess the effect of vehicle and double-inhibitor treatment 7 dpi. (H,I) Micrographs of telencephalic sections 7 days after skull injury depicting Olig2:GFP⁺ and Sox10⁺ oligodendroglia after vehicle (H) and inhibitor cocktail (NBI 74330 and CU CPT22) (I) treatment. (J) Graph illustrating the density of Olig2:GFP⁺ cells located within the injured volume after vehicle and double-inhibitor treatment. An equal volume was quantified in both conditions (p-values is based on Student’s t-test with equal variances). (K) Scheme depicting the experimental design to assess the capacity of the vehicle and double inhibitors treatment to resolve glial accumulation. (L,M) Micrographs showing telencephalic sections 7 days after skull injury and vehicle (L) or double-inhibitor (M) treatment. White arrows indicate the injury site. Note that both vehicle and inhibitor treatments failed to resolve Olig2:GFP⁺ accumulation. All images are full z-projections of confocal stack. The level of the cross-section is indicated in the inset. Scale bars in (L,M) = 100 µm; scale bars in (B–E,H,I) = 20 µm. Abbreviations: dpi: days post-injury, Inh: inhibitor. Symbol description: red triangle: vehicle; dark blue triangle: Tlr1/2 inhibitor, CU CPT22; green triangle: Cxcr3 inhibitor, NBI 74330; light blue triangle: double inhibitors, NBI 74330 and CU CPT22.